The invention relates generally to the field of photography, and in particular to photofinishing. More specifically, the invention relates to a method of photofinishing that employs an encoded data pattern placed on photographic film.
The 35 mm film system has been on the market for many decades. This film system consists of light-sensitive, AgX media spooled into a cartridge of particular construction; cameras designed to handle this film and expose it to the image of a scene; and photofinishing equipment designed to extract the film, develop it in a chemical bath, and print the image onto photo-sensitive paper. The elements of this film system have co-evolved over many decades into a coherent, working system. Many vendors supply equipment to each part of this film system.
Recently, one portion of the 35 mm film system has changed. Photofinishing equipment that scans the film and converts the image to a digital form has been introduced. Digital data, in some cases, is used directly to create a viewable print, via digital writing. In other cases, the data is stored on a writable magnetic or optical disc, for use by the customer in a computer system. In still other cases, the data is sent by a network to a website or directly to the customer""s computer. Even though this development is recent, many companies already supply this type of digitization equipment. The digitization equipment is widely dispersed. Some of the digitization equipment is placed at central locations to where the film cartridges are shipped, and other digital equipment is at retail locations.
Skilled artisans know how to record data on photographic film, either magnetically in a magnetic layer on the film, or optically as latent images on the film. The data, generally known in the imaging industry as metadata, may contain information about the captured scene, or about the photographer""s technical preferences, or even contain information on how the image should be reproduced. Metadata is information associated with a picture or with a set of pictures, other than the actual image information itself. When an image has been digitized, we refer to the information that recreates the image as the pixel data; everything else is therefore metadata.
One class of metadata records a photographer""s request to modify the reproduction of a specific frame of film. For example, the photographer may request that the central region of the film frame, which is roughly one-quarter the area of the entire frame, be used to produce the final print (otherwise known as, pseudo zoom). Alternatively, in another implementation, the photographer may request that the image be rendered as monochrome and have a sepia tint (i.e., a sepia feature).
A second class of metadata adds information that does not modify the reproduced image. For example, the date on which each frame was exposed may be stored as metadata.
In short, metadata may describe a scene; the device used to capture the scene; the intent of the photographer; the context of the picture; or a request for certain products to be created from the picture data. Metadata may also be used to improve the quality of reproductions; to classify pictures for easy retrieval; or for creating output products.
Metadata is most useful when it is generated directly and automatically in the camera as the scene is captured or shortly thereafter. However, the metadata has to be transported by intermediate components. Afterwards, the metadata is read and used by the processing equipment that creates prints or manages digital data.
In the 35 mm film system, the only practical mechanism for associating metadata with the image or with a roll of images at the capture point is optically marking the film itself. These optical marks must be made in such a way that they can be differentiated from and not interfere with, useful scene recording. They must also be made in such a way that the equipment reading the film can easily measure and interpret them.
In the case of optically recorded metadata, the metadata can be read by photofinishing equipment to control photographic processing and printing operations. For example, U.S. Pat. No. 5,870,639 issued Feb. 9, 1999 to Constable et al. entitled Optical Data Recording Circuit For A Photographic Camera discloses recording latent image metadata called xe2x80x9cfat bitsxe2x80x9d on the marginal edges of an image frame and outside of the area reserved for the image. The areas reserved for the image are herein referred to as the safe frame areas of the film strip. The fat bits are later used to control the aspect ratio of a print produced from the image frame.
It is also known to optically record data such as time and date by superimposing the time and/or date on the image within the safe frame area of the film. See, for example U.S. Pat. No. 5,519,463 issued May 21, 1996 to Nakamura et al. entitled Data Imprinting Device For A Camera. This data, however, is not intended to be machine readable, and is optically reproduced and viewable solely when a print of the image is made.
There are a large variety of 35 mm film cameras on the market. They range from one-time-use cameras that sell for less than ten dollars, to professional cameras that sell for thousands of dollars. Similarly, the features desired by users of these cameras vary greatly. Also, the allowable cost of a marking device for metadata in these cameras varies greatly. Nevertheless, the same photofinishing equipment is generally used for all 35 mm color film, no matter what camera places the image on the film.
In considering the introduction of cameras that write optical metadata to a 35 mm film, the placement of these optical marks on the film is critical. One choice is to place the marks outside the safe frame areas, hence, either between or outside the film""s perforations. A second choice is to place the marks in the safe frame area, but between the framed images. From the viewpoint of the camera designer, all of these methods have advantages and disadvantages, and all are quite practical. Both methods have the disadvantage of a limited available area and a limited data storage capacity.
Although digital scanning is becoming quite common, the processing equipment still requires special equipment adaptations in order to handle any information recorded outside the safe frame area of the film. See for example U.S. Pat. No. 5,665,950 issued Sep. 9, 1997 to Rottner et al. entitled Fat Bit Bar Code Reader, which discloses a bar code reader for reading xe2x80x9cfat bitsxe2x80x9d recorded on the edges of photographic film. Because of the extra expense and complexity, these special equipment adaptations for handling information recorded outside of the safe frame area of photographic film are not likely to be widely deployed.
From the viewpoint of the photofinishing equipment designer, the aforementioned methods present very different issues. As noted above, there are many types of digital photofinishing equipment on the market. In every case, the ability to read this additional optical metadata is an add-on to an existing design. In most cases, there is a need to retrofit equipment already in the field. Designing photofinishing equipment requires balancing mechanical, optical, electronic, and software tradeoffs. The introduction of additional information on the film, outside the safe frame area, poses substantial challenges in all these fields. In particular, the software design of photofinishing systems is quite complex, because there are many layers of software between the optical reading device and the image processing subsystem.
Because metadata has proven so useful, there is substantial interest in increasing the amount of metadata embedded in film. However, heretofore substantial photofinishing hardware and software modifications were required to accommodate increased embedded metadata.
There is a need, therefore, for an improved method and apparatus for optically recording and recovering metadata from photographic film that does not require additional and costly photofinishing hardware modifications.
The need is met according to the present invention by providing a photofinishing method, including the steps of: exposing machine readable metadata and a scene image within an entire safe frame area on a filmstrip; processing the filmstrip to produce a visible image including the machine readable metadata and the scene image; scanning the safe frame area to produce a digital image; extracting the machine readable metadata from the digital image; extracting the scene image from the digital image; and processing the scene image according to the extracted machine readable metadata.
This invention has the advantage that the additional metadata is scanned and transported through the photofinishing system easily, requiring entirely no modification in hardware and only minor modification in a small area of software.
These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings.